Technical Possible fuel system problem

[Mad Matt]

I'm having a problem with dropping revs and low rev hesitation (no stalling yet). I'm not sure if this describes it well, but in any case it made me think of the fuel supply.

I had the garage change the fuel filter and the car went like a dream for a week or so, then suddenly it was back to it's old ways. I've tried petrol cleaner, but to no avail.

I saw BarchettaGirl seemed to have a similar problem in another thread, but as that wasn't the topic I didn't want to hijack it!

Any ideas? Does anyone know how she solved her problem in the end?

Cheers,

Matt.

 

[BILL33]

Clean the butterfly.I have the same problem in my Punto HGT from time to time and in my B once.Remove the rubber hose that is attached in the throttle ,start the engine ,and spray curb cleaner inside the butterfly and rev her up in order to open the butterfly for the cleaner to get inside .Thats what i do .

 

[Mad Matt]

Thanks I'll give that a go, just seems strange that it works for a while after the garage have had it.

Matt.

 

[ricky952]

i have same problem matt 6 months now you drive go to stop revs drop below idle but does not stall then goes back to idle does this sound right
go to pull away slight flat spot on take away in first got to give touch of revs to avoid stalling i have heard it might be lambda sensor still looking for answers before i tackle anything

 

[Mad Matt]

Well, I bought the cleaner, if it stops raining I'll give it a go, and let you know.

Cheers,

Matt.

 

[ricky952]

i have just cleaned mine not driven it yet was dirty inside
matt you will need to get a jubilee clip to replace factory clip
you will see the end of the factory clip prise with screwdriver and it should come away i also used wipes to clean inside the housing so the butterfly seals properly have fun will let you know if car runs better

 

[Mad Matt]

Thanks for the advice, yes I had to use a new clip, although I did try the old one

The butterfly valve was filthy, black oily gunk... I use an old piece of clean cloth to give it a wipe as much as possible, and then used carb cleaner.

The car spluttered a lot when I started it up but within five minutes of driving it began to run better.

So far it now seems to run a lot better.

I'll post again in a week or so to say if it's a long term fix or not.

Cheers,

Matt.

 

[ricky952]

drove my bee in town today like a new car, matt did you spray the carb cleaner right down the intake thinking about that myself for a deeper clean
mine had never been cleaned in its 10 years of life still had original clip

 

[Mad Matt]

Mine's a '97 and looked like it hadn't been cleaned since the day it was born!

I opened the valve and gave it a wipe, then gave it a good spray all the way down, and tried to make sure I got both sides of the valve too.

Yes, it is like a different car, a more pleasant one to drive

 

[Mad Matt]

Quick update: I noticed the problem a lot when I sit in traffic, which has been the case for the last two days. It's much better than it was, but not perfect.

I'll try cleaning it again in a week or so in case I left some muck behind.

 

[ricky952]

exact same as mine matt but it has cured mine make sure clean edges of butterfly as well and spray the 2 throttle springs

 

[Mad Matt]

Didn't do the springs, so thanks for the tip. I'll try that tonight, but I won't get a chance to drive it again for a week :-( , I'm off to Turin for a short break.

Cheers,

Matt.

 

[ricky952]

hows the car matt drove mine to ayrshire and back today approx 140 miles no flat spots at all maybe just me but fuel consumption seems better aswell

 

[Mad Matt]

Still not right, I'm afraid. It seemed to go 'off' after a couple of days in traffic, although I did get over 40mpg from the first tank after the clean.

I gave it a clean again on Saturday, but after a quick run I don't think that's fixed it. I'm not sure if it's just filthy after 10 years of driving, or there's something else. This time I used a tooth brush instead of a cloth and it came off black! I also gave the springs a spray and brush, but the mechanism seems to open and close smoothly, so probably not the cause.

It's still much better than where I started from, but it's not as smooth as when I got it back from the garage last time.

Unless anyone else has got an idea I'm thinking of:
1. Check the fitting of my CDA in case I'm bringing in dirty air somewhere.
2. Use some pertol cleaner in case the injectors are also a problem.
3. Clean again to see if I can clear out the last of 10 years worth of dirt.

Cheers,

Matt.

 

[superspotter]

A full bottle of injector cleaner with you next full tank of fuel would be my first move.

 

[DanGil]

I've fitted a catch tank to my hgt to stop the problem, 3 years on its still perfectly clean and running fine. You really need to take the throttle body off to give it a proper clean. If you do, hold it up to the light and there probaly won't be a small gap all the way around the edge of the butterfly, the gap is needed to idle/start up properly.

 

[Mad Matt]

Isn't that more than a trivial exercise? I suppose what I mean is how long did it take and is it more than a screw driver job?

 

[DanGil]

Just a suggestion, thats all.

 

[Alan.D]

Isn't that more than a trivial exercise? I suppose what I mean is how long did it take and is it more than a screw driver job?

It's pretty tight under the bachetta's bonnet, but a bit of time & care and you'll manage it easy.

Dangil, matt wasn't having a pop.

 

[Mad Matt]

Absolutely not! No 'pop' intended. I've done minor work on cars, on and off, for some years but I'm no expert, which is why I was wondering how hard a job it would be.

All suggestions are appreciated